Predictive factors for post-total thyroidectomy hypocalcaemia

Post total thyroidectomy hypocalcemia is a frequent and serious complication of thyroid surgery. Predictive Factors of its risk, justifying the prescription of preventive treatment are to be determined.

To identify the predictive factors of hypocalcemia secondary to total thyroidectomy.

We report a retrospective study involving 260 patients operated with total thyroidectomy at the ENT department of the military hospital of Tunis over a period of 5 years. A statistical study was carried out to find out predictors of hypocalcemia.

Our patients were women in 85% of cases with an average age of 49 years. The incidence of postoperative hypocalcemia was 31.9%. Hypoparathyroidism was definitive in 1.1% of cases. Univariate statistical analysis identified the following factors: presence of cervical swelling at the initial physical exam, gradual onset of mass, thyroid nodule size greater than 4 cm, preoperative calcium level <2.25 mmol/L, one-shot thyroidectomy operating time, histological appearance of thyroiditis and accidental excision of a parathyroid gland. The factors retained in the multivariate study were: gradual onset of mass, nodule size> 4 cm, preoperative calcium level <2.25 mmol/L and histological appearance of thyroiditis.

Post total thyroidectomy hypocalcemia is linked to intrinsic factors of the thyroid, preoperative calcium level, preoperative and intraoperative parathyroid lesions. Its prevention would include: supplementation of patients with hyperthyroidism or with low preoperative calcium levels, systematic identification of the parathyroid glands and their reimplantation in cases of devascularization.